This is an absolutely beautiful team, a true definition of 5th gen HO without Deo-D. Really the only thing i can point out is that Celebi gives you a ton of trouble as it can potentially wall 3 of your pokemon, Garchomp, Breloom, Starmie, and T-wave Volcarona if they're crazy enough to stay in or if you misplay, SCRUB. The only way you can handle it is ouplaying or just setting up early with Dragonite which works of course.
I've tested and worked with you on this team so much that the only thing Ii can suggest is possibly lum over life orb on volcarona but then you lose out on your KOs so ._. Maybe Fire Fang over Swords Dance on Chomp or Signal Beam on Starmie if you dat cray
I question the use of Volcarona on your team. Lucario already gives you an offensive check to opposing Scizor and Dragonite deals with sun teams. It doesn't open holes to opposing teams for your fellow SD'rs since it will be hurting the special pivots and it also forces you to run Starmie. When Lati@s or any other Special Dragon / big threat switches in you are going to lose a Pokemon and leading with Sash Breloom to try and sleep it is the shakiest strategy. Opposing Rain teams seem problematic if you can't get Stealth Rock off the field since Keldeo is going to 2HKO Starmie and OHKO Dragonite. Icy Wind Keldeo, as seem from earlier, is going to be a pain since if you try to set up Dragonite on it, it will lower your speed and force you to lose Dragonite. Icy Wind Jirachi is annoying too!!!!!!!!!!!!! (lol). Dragonite can set up on Breloom after the sash is broken or even Volcarona and proceed to pracically 6-0 you. All speed boosters are annoying as hell and this seems particularly problematic. Trick Room Reuniclus and the likes also are major pains in the ass. Using a Scarf Jirachi instead of Volcarona fixes most of your problems; however, if you think the lack of a Scarfer isn't terrible then you can try an SD Scizor. Rethink the use of Starmie's teamslot with Volcarona out of the picture as Dragonite doesn't necessarily need Rapid Spin support if your team is very hyper offensive-esque.
Very cool team, I notice a strong weakness for dragons though, especially Dragonite, Salamence from the physical and well Latios and Latias the special part, on virtually every one of their attacks, the only steel you have is Lucario, but you can of course do rely on him to cash a Outrage / Draco Meteor, I would suggest also as said by Princess Bri one Scarf Jirachi instead of Volcarona, as the steel as Scizor, Ferrothorn already manage them very well with Lucario and Breloom, who also Spore for sleep and do statup on them, Volcarona would force often the entry of Starmie to remove the Stealth Rock. Scarf Jirachi rectify the problem with the dragons, as it can afford to take Draco Meteor / Outrage and counter with Ice Punch, the set I suggest is this: 4 HP / 252 Atk / 252 Spd Fire Punch - Ice Punch - U-Turn - Iron Head Jolly nature.
While on paper there seems to be a severe weak to dragspam, through careful play and thinking its really quite easy to avoid being swept. I really wish I had a replay of my match vs sogeking to show you exactly how. Momentum is the most important part of this team and as long as I am dictating how the match is going no opposing dragon is going to set up on me. When facing drag spam the most crucial dragon to remove is the scarfer. This isnt too difficult as you can easily draw out moxie mence with say dragonite and switch out to lucario for the kill. By incapacitating one dragon with breloom (obviously don't lose it cheaply) and taking one out with lucario, any danger is greatly alleviated. I've only ever once lost to a drag spam team and that was largely due to LO mamoswine + 4 dragons proving too much of an overload.
As for volcarona there is no way im going to replace it with jirachi. So many teams are volcarona weak and it simply monsters those cookie cutter sand balance teams that have become the norm in this metagame. While jirachi may be a good idea Breloom would be the mon to replace, not volcarona. In fact I used scarf healing wish latias in that slot on a number of occasions to mitigate the threat of dragons. So my suggestion is if you're having trouble with dragons, try out latias > loom.
Great non Deo-D HO team. I don't rate much but once your set up sweepers has set up im pretty sure you wont want the sweep to be uninterrupted so Lucario would appreciate Cruch>Ice Punch if jelliscent is still out there late game. Also a spread of 144 HP / 84 Def / 120 SAtk / 160 Spd with Timid Nature gives you volcarona more physical bulk meaning an easier time setting up more quiver dances to sweep since you dont have reliable recovery outside giga drain on rona in case starmie cant keep rocks off the field. Speaking of recovery you could use roost>giga drain and leftovers>life orb since my spread allows you more quiver dances as compared to immediate power and it will help volcaronas longetivity.
First of all, I'd change a little your Garchomp set, an EVs spread of 4 HP / 252 Atk / 252 Spe with the same moveset, with the same nature and with Focus Sash should work better than your current one on your team because on an Offensive team as yours Garchomp doesn't need EVs on HP to have more staying power and it doesn't need Rocky Helmet too, Focus Sash is simple a better choice on Lead Garchomp because it allows you to setup Stealth Rock with more chances than Rocky Helmet and put Stealth Rock is the first goal that an Offensive team should have since it allows to kill opponent's team more easily of course and because it's useful against threats such as Tornadus, Thundurus-T, Dragonite, Salamence and opposing Volcarona too.
I also notice that your team lacks a revenge-killer and it lacks a more bulk Steel-type to check Dragon-types too, so I'd go with Princess Bri and Mr. Green's suggestion to use Choice Scarf Jirachi replacing Volcarona which is a good revenge-kill and a good check to Dragon-types too. An EVs spread of 252 Atk / 4 SpD / 252 Spe with a moveset of Iron Head, U-Turn, Ice Punch and Fire Punch, with Jolly nature and with Choice Scarf of course should work fine on your team.
After that, try Bullet Punch replacing Ice Punch on Lucario, which is useful against Terrakion, Gengar and Choice Scarf Tyranitar which can revenge-kill your current Lucario easily, this is optional, however, if you prefer Ice Punch you can keep it.
As last thing, I suggest you to use Reflect Type replacing Ice Beam on your Starmie which would help you against Tyranitar and Choice Band Scizor which can trap and kill quite easily your Starmie. Reflect Type allows you to avoid Tyranitar and Choice Band Scizor's Pursuit, which can be really useful since Starmie is an important member of your team, it has Rapid Spin, it checks Keldeo and so on, so try it in some battles and see how it works.
Anyways it looks like this team sorta hates DRAGONS as Princess Bri pointed out. Latios can kinda come in and spam Draco Meteor or just Surf/Psyshock which your team has trouble taking. I do see that Latios does put its team in a vulnerable position after Dmeteor spam because it opens up a setup opporunity for Lucario at -2, but that strat is less prevalent if they have a hard stop to SD Lucario like Scarftar or Fire Punch Scarf/Fast Jirachi [like the shakeitup set], plus Latios can always come in later in the game and clean. DD Dragonite could also prove problematic for this team since it can probably net a DD on unboosted Breloom or Volcarona [provided something is slept] and then sorta proceed to murder everything with +1 Fire Punch and Outrage [I believe DClaw does just fine too, as it ohkos starmie after rocks]. To maybe have a better answer to the dragon problem I think you could try a SD Scizor over your Lucario. Scizor has a lot better time coming in on Draco Meteor and can hit Latios hard with Bug Bite/Bullet Punch , killing it or forcing it out and Scizor is also able to 2hko Dragonite with Bullet Punch if you're able to get SR up; so at least you have a "stop" to it if it gets into a +1 outrage. Scizor still has pretty awesome synergy with the rest of the team because it can help wear down the very annoying Skarmory, who takes a nice : 63.47% - 74.55% from +2 Superpower if it comes in [and is then forced to whirlwind] and if it gets anything but Garchomp and Breloom then you can force it out and keep forcing it into SR while double switching to Volc/Starmie to get it down to the point where +1 Outrage or +2 Mach Puns is killing it. This strategy actually works a lot better when Nite has fire punch which straight up 2hkos at +1 so if you wanna change to that it could help but its still fine if you wanna keep EQ. Sick team though, congrats on the peak.